Poles, such as ski poles and their end pieces, whether a basket or an alternative design, are designed by taking into consideration a number of different parameters. First of all the weight of the pole is important. This pertains to the weight in general but especially to the weight of the pending part of the pole, i.e. the part of the pole furthest away from the handgrip. The handgrip will act as a fulcrum point during use and the mass rotating about the fulcrum point will thus invoke a moment of inertia. The weight towards the lower end of the pole will greatly influence the moment of inertia deriving from the length of the pole and the mass along the length of the pole and also any mass close to the end of the pole, i.e. the end piece. This will influence the stability of the pole as well as other properties of the pole in use. In general the pole shall be easy to handle and stable in addition to having a advantageous shape when considering wind resistance in use.
One way of enhancing the design of the pole is thus to design the actual pole body in a way that reduces or limits the weight towards the lower end of the pole.
Another approach to the design of the pole is to limit the weight of the end piece at the end of the pole, as this represents the mass furthest away from the fulcrum point for the pole and thus represents a substantial contribution to the moment of inertia. If the end piece is a basket it must still be able to perform its role and fulfill its purpose in providing a thrust bearing surface against the snow, enabling the user to use the ski pole efficiently to provide a forward thrust and thus gain speed ahead. The balance between the weight of the basket and the robustness and strength of the end piece, such as a basket may be a difficult compromise on the path to optimizing the motion dynamics of the ski pole. The compromise may end up with a more fragile basket.
The fastening of the end piece to the pole body, i.e. the connection between the end piece and the pole may also affect the motion dynamics of the pole as the connection may contribute to the weight close to the end of the pole and as the connection is close to the lower end of the pole the weight may greatly influence the moment of inertia.
Furthermore, if the end piece, in the endeavor to reduce the weight of the end piece, turns out to be of a more fragile design, it may we advantageous to be able to replace the end piece in the event it is damaged or destroyed. Especially when taking into account that materials in modern poles are rather expensive, it may be advantageous to be able to continue to use the pole body if it is intact, by replacing a nonfunctional basket.
For other reasons it may also be advantageous to be able to replace the end piece. It may then be possible to use the same pole body for several purposes. E.g. a basket used on ski poles will ideally have different shapes and sizes depending on the snow conditions as the thrust bearing surface of the basket may have variable size and shape. Hence, a replaceable basket would be advantageous. Also the user could be able to use the same poles for snow skiing and roller skiing. As the pole body may be used for several different purposes, the end piece could also be replaceable.
In most cases however the end piece such as e.g. a basket is attached to the pole using an adhesive e.g. glue and is thus not replaceable without professional equipment and a time consuming process, if at all possible. In alternative embodiments the end piece may be attached to the pole body through a coupling e.g. a bayonet coupling. Prior art solutions may be found in DE 698 14 553 T2 describing a bayonet coupling. EP 1 676 608 shows a similar solution with a locking mechanism and U.S. Pat. No. 4,669,752 teaches a locking mechanism between a basket and a ski pole.
Finally, as the design of poles is developed and especially ski pole bodies, the bodies may come in different shapes and sizes. The solution for fastening an end piece to the end of a pole must thus be versatile and general and should encompass various pole designs.